Gail, a question about sunscreen and skin products with retinyl

Quadmom and I have been reading about how products containing retinyl-A might actually accelerate skin cancer, and that we should discontinue using sunscreens that contain this and oxybenzone. But what about the retin-A that I mix with my moisturizer at night for acne and general freshening up? Is this also making me more susceptible? Should I quit using it in summer or only use it when I won't be in the sun? (Which is pretty much never, since I'm not a mushroom!)